1. Field of the Invention
The present invention relates to an electronic device tray, an electronic device tray transporting apparatus, and an electronic device testing apparatus, more particular relates to an electronic device tray and electronic device tray transporting apparatus suitable for holding and conveying integrated circuit (IC) chips and other electronic devices for testing the electronic devices and to an electronic device testing apparatus having such a tray or tray carrier.
2. Description of the Related Art
In the process of production of semiconductor devices etc., a tester for testing the finally produced IC chips and other electronic devices becomes necessary. In such a tester, a large number of IC chips carried on a tray are picked up by a suction apparatus and conveyed to over a test head of the tester. Each IC chip is brought into electrical contact with the test head for testing the IC chip. When the test is completed, the IC chips are conveyed out from the test head by a suction apparatus having suction pads and reloaded on trays in accordance with the results of the test so as to sort them into categories such as good chips and defective chips.
In this kind of tester, there is a type which is provided with trays for conveying the IC chips circulating in the tester (hereinafter referred to as xe2x80x9ctest traysxe2x80x9d) in addition to the trays for holding the pre-test IC chips and holding the post-test IC chips (hereinafter referred to as xe2x80x9ccustomer traysxe2x80x9d). In this type of tester, the IC chips are reloaded between customer trays and test trays before and after testing, a plurality of IC chips are conveyed inside the tester in the state loaded on test trays, and the IC chips are protected during conveyance.
In this type of tester, since the plurality of IC chips are conveyed inside the tester in a state loaded on test trays, restraining mechanisms are provided for preventing them from jumping out from the test tray due to vibration or shock during conveyance (for example, see FIG. 7 of Japanese Unexamined Patent Publication (Kokai) No. 9-43309).
In the tester of the related art, however, since restraining mechanisms are provided to hold each and every IC chip, the exact same number of restraining mechanisms as the IC chips becomes necessary. Not only is there a problem cost-wise, but also use of the same mechanisms is difficult when the ICs are different in shape. In this sense as well, the restraining mechanisms had to be specially designed.
There is also known a tester which covers the area above the test head by a chamber section to create an air-tight space inside, conveys the IC chips above the test head and there pushes the IC chips against the test head for connection, then tests them while making the inside of the chamber section a high temperature or low temperature state.
In this type of tester, the test trays are successively made to move in the substantially vertical direction inside the chamber section and thermal stress is applied gradually to the IC chips attached to the test trays. The test trays are made to move in the substantially vertical direction to gradually apply thermal stress to the IC chips since arrangement of a plurality of test trays in the substantially vertical direction helps make the chamber section compact.
In the tester of the related art, as a tray carrier for making the test trays move in the substantially vertical direction, use is made of a vertical carrier which detachably holds all of the trays arranged in the substantially vertical direction by separate holding members and makes them move successively downward one level at a time in the vertical direction.
In the tray vertical carrier in the tester of this related art, however, since the mechanism holds each of the trays in the vertical direction and makes them move successively downward, there is the problem that the mechanism becomes complicated. Further, the time required for a tray to be moved from the uppermost level holding member to the lowermost level holding member corresponded to the number of levels. There was the problem that even when the number of trays arranged in the vertical direction was small, the same amount of time was taken as when there were a large number of trays. Further, there was also the problem that it was not possible to increase the operating speed of the mechanism due to the design of the tray vertical carrier of the related art.
Further, inside the chamber section of the tester, it is necessary to not only make the test trays move in the substantially vertical direction, but also make them move in the substantially horizontal direction. A tray horizontal carrier is therefore also provided inside the chamber section.
The tray horizontal carrier of the related art, however, made the trays move in the horizontal direction by a belt conveyor system, so there was a problem in the mechanism for making the trays stop at predetermined positions. For example, in the tray horizontal carrier of the belt conveyor system of the related art, to make a tray stop at a predetermined position, a stopper member was made to abut against the tray conveyed by the belt conveyor to make the tray stop, the stopped tray was detected by a position sensor etc., then the belt conveyor was made to stop. Next, when making the tray move to another position, the stopper member was retracted, then the belt conveyor was driven, and, in the same way as explained above, a stopper member was used to make the tray stop at another stopping position.
Therefore, a stopper member and sensor became necessary for every one of the plurality of stopping positions. Further, an actuator member for driving the stopper members was required. The mechanism therefore become complicated. Further, since a tray was made to abut against a stopper member to make the tray stop, a shock was given to the tray due to its striking the member, the trays would slip against the belt until the conveyor was stopped, and trouble such as wear of the trays and belt would occur. Further, since a tray was made to strike a stopper member to stop it, the stopping position easily would become deviated and a mechanism for positioning the tray had to be separately provided.
A first object of the present invention is to provide an electronic device tray for conveying for example an IC chip or another electronic device and having a particularly simple structure of a restraining mechanism.
A second object of the present invention is to provide an electronic device tray, an electronic device tray transporting apparatus, and an electronic device testing apparatus which, when a tray for conveying IC chips and other electronic devices is conveyed in the substantially vertical direction, are simple in mechanism, fast in operating speed, and enable a tray to be moved particularly quickly in the substantially vertical direction when there is a small number of trays.
A third object of the present invention is to provide an electronic device tray transporting apparatus and an electronic device testing apparatus which, when a tray for conveying IC chips or other electronic devices is conveyed in a substantially horizontal direction, use relatively simple mechanisms to easily make the tray accurately stop at a predetermined position, reduce the load acting on the tray, and suffer from less trouble.
A fourth object of the present invention is to provide an in-chamber member movement mechanism, and an electronic device testing apparatus using the same, which can easily make a tray carrier or other in-chamber movement member accurately stop at a predetermined stopping position by a relatively simple mechanism, reduce the load acting on the movement member, and suffer from less trouble, in particular an in-chamber member movement mechanism, and an electronic device testing apparatus using the same, which can effectively prevent condensation when holding the inside of the chamber section in a low temperature state.
To achieve the first object of the present invention, according to a first aspect of the present invention, there is provided an electronic device tray comprising a tray body provided with a holder in which an electronic device under test is held and a shutter attached movably with respect to the tray body for opening and closing an opening of the holder.
In the electronic device tray according to the first aspect of the present invention, a shutter for opening and closing the opening of the holder is provided. When carrying and conveying an electronic device under test, the shutter is closed, while when reloading the electronic device under test, the shutter is opened. Therefore, the electronic device under test is prevented from jumping out during conveyance. Further, since the shutter does not have to be provided for each holder and may be provided commonly for at least several holders, the restraining mechanism of the electronic devices becomes streamlined and the cost can be reduced. Further, in this electronic device tray, since the shutter slides with respect to the tray body to prevent an electronic device under test from jumping out, there is no need to change the shutter even if the electronic devices under test differ in shape and consequently the shutter can be made more general in use.
Note that one shutter is most preferably provided for one electronic device tray, but it is also possible to divide the holders into several groups and provide a shutter for each group.
The electronic device tray of the present invention preferably further has a spring or other elastic member imparting a biasing force to the shutter in the direction closing the opening of the holder. In particular, if such elastic members are provided at both ends of the shutter, the balance of the shutter at the time of opening or closing becomes good and the shutter can be easily opened or closed by gripping just its center.
The shutter preferably is provided with an engagement portion for engagement with an operating mechanism provided separately from the electronic device tray so as to make the shutter move with respect to the holder and open or close the opening.
The shutter preferably is attached to be able to freely slide with respect to the tray body in the substantially perpendicular direction with respect to the longitudinal direction of the shutter by a center guide member arranged at the substantially center position of the shutter in the longitudinal direction.
Preferably side guide members for guiding the sliding movement of the shutter in the substantially perpendicular direction with respect to the longitudinal direction are provided at the two end positions of the shutter in the longitudinal direction and the clearance between the center guide member and the shutter is smaller than the clearance between a side guide member and the shutter.
The electronic device tray is sometimes subjected to a high temperature or a low temperature and the resultant thermal stress makes the tray body and the shutter expand or contract. In this electronic device tray, however, since the shutter is supported to be able to freely slide by the center guide member at the substantially center position of the tray body in the longitudinal direction, even if the shutter expands or contracts due to heat, the expansion or contraction is distributed to the two ends from the center guide member. Therefore, the dimensional error due to the thermal expansion or thermal contraction, even at the maximum, becomes half of that of the case where the shutter is supported at only one side and thereby it is possible to reduce the error due to thermal expansion or the error due to thermal contraction between the tray body and the shutter.
Preferably a sliding member reducing the friction when the shutter slides with respect to the tray body is provided between the shutter and the tray body.
By providing a sliding member between the tray body and the shutter, interference between the shutter and the tray body at the time of the opening or closing of the shutter is prevented, a smooth opening/closing operation becomes possible, and there is no longer damage to one or the other. Even if the sliding member becomes worn, since it is sufficient to replace only the sliding member, the lifetime of the electronic device tray becomes lengthened.
The tray body is preferably formed with a positioning hole for engagement with a positioning pin provided separately from the electronic device tray. The positioning pin is for example provided on a suction head for picking up an electronic device from the tray. The positioning hole is preferably provided detachably with an intermediary member of a hardness lower than that of the positioning pin. Note that it is also possible not to provide the intermediary member in the positioning hole, but to attach the intermediary member at the positioning pin.
The engagement between the positioning pin and the positioning hole results in the contact surfaces of the two becoming worn and thereby a reduction in the positioning accuracy, but it is possible to make the wear occur at an intermediary member by providing an intermediary member of a low hardness at either the positioning pin or positioning hole and thereby possible to prevent wear of the positioning pin and positioning hole. Further, since the intermediary member is provided detachably, when it becomes worn to a certain extent, it is sufficient to replace just the intermediary member.
The holder is preferably defined by at least two blocks of the same shape attached to the tray body in a detachable manner. By using blocks of the same shape, it is possible to reduce the types of parts making up the electronic device tray.
It is preferable to make the shape of the holder variable by changing the position of attachment of the blocks to the tray body. Even if electronic devices under test differ in shape, the same blocks can be used in common, universality can be imparted to the parts, and costs can be reduced.
Preferably a guide portion for positioning the input-output terminals of the electronic device under test is provided at the bottom of the holder.
For example, with a ball grid array (BGA) type IC chip of a chip size package (CSP), the dimensional accuracy of the outer periphery of the package mold is extremely rough and the accuracy of positioning of the outer circumferential shape and the solder balls is not necessarily guaranteed. Therefore, if positioning in the holder using the outer periphery of the IC package, the solder balls are liable to be pressed against the contact pins in the measurement portion in an offset state.
In the present invention, however, since a guide means for positioning with respect to the input-output terminals of the electronic device under test is provided at the holder, it is possible to directly position the input-output terminals and ensure the dimensional accuracy with the contact pins etc.
The holder is preferably formed with the through portion through which the detection light for detection of the presence of an electronic device under test may pass. By doing this, it is possible to detect if there is an electronic device at a holder after reloading the electronic devices under test. The xe2x80x9cthrough portionxe2x80x9d referred to here is a broad concept including holes, cutaway portions, and other various shapes and structures.
The through portion is preferably provided at the tray body and/or shutter. By providing the through portion at each of the tray body and the shutter, it is possible to detect the presence of an electronic device under test in a short time using the idle time such as when an electronic device tray with a closed shutter is being moved.
According to a second aspect of the present invention, there is provided an electronic device tray for conveying an electronic device under test having either of a positioning pin or a positioning hole and having provided detachably at either of the positioning pin or positioning hole an intermediary member of a hardness lower than that of the other.
In general, the engagement between the positioning pin and the positioning hole results in the contact surfaces of the two becoming worn and thereby a reduction in the positioning accuracy, but in the present invention it is possible to prevent the wear of the positioning pin and positioning hole by providing an intermediary member of a low hardness at either the positioning pin or positioning hole. Further, since the intermediary member is provided detachably, when it becomes worn to a certain extent, it is sufficient to replace just the intermediary member.
According to a third aspect of the present invention, there is provided an electronic device tray having at least one holder accommodating an electronic device, wherein a projection enabling the tray to be stacked in the substantially vertical direction at predetermined intervals is provided at the top surface or bottom surface of the tray.
The electronic device tray is preferably provided with a shutter for opening and closing an opening of the holder.
When stacking electronic device trays in the substantially vertical direction, predetermined spaces are formed between the trays. As a result, when arranging the trays in the chamber section, the high temperature or low temperature of the atmosphere in the chamber section is conducted well to the trays and the trays can be easily set to uniform temperatures.
To achieve the second object of the present invention, there is provided a carrier for an electronic device tray according to the first aspect of the present invention for conveying a tray holding at least one electronic device in a substantially vertical direction, comprising a tray end holding member able to detachably hold an end of the lowermost level tray positioned at the lowermost level among stacked trays; a tray elevating member abutting against the bottom surface of the lowermost level tray and conveying the lowermost level tray downward or upward; and an actuator member for driving the tray end holding member So as to release the hold on the lowermost level tray by the tray end holding member and hold the end of another tray next arriving at the lowermost level position when the tray elevating member abuts against the bottom surface of the lowermost level tray and the lowermost level tray becomes supportable by the tray elevating member.
In the present invention, the actuator member is not particularly limited, but for example an air cylinder or other pressure cylinder, electromagnetic drive actuator, piezoelectric drive actuator, motor actuator, etc. may be mentioned.
The electronic device tray transporting apparatus preferably further is provided with a tray horizontal carrier arranged below the tray end holding member so as not to interfere with the elevating movement of the tray elevating member, receiving the lowermost level tray when the tray elevating member descends, and able to move the same in the substantially horizontal direction.
Note that in the present invention, the xe2x80x9csubstantially vertical directionxe2x80x9d means not only the vertical direction in the strict sense of the term, but also cases of some inclination from the vertical direction. Further, similarly, the xe2x80x9csubstantially horizontal directionxe2x80x9d means not only the horizontal direction in the strict sense of the term, but also cases of some inclination from the horizontal direction.
The electronic device tray transporting apparatus preferably further is provided with a rail holding the tray horizontal carrier movably in the substantially horizontal direction.
The electronic device tray transporting apparatus preferably further is provided with a drive wire connected to the tray horizontal carrier and making it move along the longitudinal direction to make the tray horizontal carrier move in the substantially horizontal direction.
The electronic device tray transporting apparatus preferably is further provided with a drive motor for winding up or unwinding the drive wire to make the tray horizontal carrier move along the substantially horizontal direction by the drive wire.
In the electronic device tray transporting apparatus according to the first aspect of the present invention, the trays are successively stacked on the lowermost level tray held by the tray end holding member. Unlike in the related art, each of the stacked trays is not held by a tray end holding member. Therefore, when there is a small number of trays to be stacked, only the lowermost level tray among the small number of stacked trays is held by the tray end holding member.
The bottom surface of the lowermost level tray among the stacked trays abuts against the tray elevating member. When the lowermost level tray can be supported by the tray elevating member, the tray end holding member is driven by the actuator member to release the hold on the lowermost level tray by the tray end holding member. Further, by again driving the tray end holding member by the actuator member, the tray end holding member holds the end of another tray next arriving at the lowermost level position.
The lowermost level tray held by the tray elevating member is conveyed downward or upward by the tray elevating member and for example is placed on the tray horizontal carrier and conveyed in the substantially horizontal direction. By doing this, the trays positioned at the lowermost level among the stacked trays are successively conveyed by the tray vertical carrier. Accordingly, when there is a small number of stacked trays, a tray is conveyed from the uppermost level to the lowermost level in a waiting time of just the time corresponding to the number of stacked trays.
Note that in the related art, since the trays were made to descend for each level of the tray end holding members without regard as to the actual number of trays, a waiting time corresponding to the number of levels of the tray end holding members was required and consequently time was taken. In the electronic device tray transporting apparatus according to the first aspect of the present invention, since the mechanism is simple, the operating speed is fast.
To achieve the third object of the present invention, the electronic device tray transporting apparatus according to the second aspect of the present invention is provided with a tray horizontal carrier for conveying a tray holding at least one electronic device in the substantially horizontal direction and a drive wire connected to the tray horizontal carrier and making it move along the longitudinal direction to make the tray horizontal carrier move in the substantially horizontal direction.
The electronic device tray transporting apparatus preferably is further provided with a rail for holding the tray horizontal carrier movably in the substantially horizontal direction.
The electronic device tray transporting apparatus preferably is further provided with a drive motor for winding up or unwinding the drive wire to make the tray horizontal carrier move along the substantially horizontal direction by the drive wire.
In the electronic device tray transporting apparatus according to the second aspect of the present invention, since the tray horizontal carrier is conveyed in the substantially horizontal direction by the drive wire, it is possible to make the tray horizontal carrier stop at the accurate position by controlling the amount of movement of the drive wire in the longitudinal direction. The amount of movement of the drive wire in the longitudinal direction can be relatively easily controlled by using for example a step motor as the drive motor. Further, unlike in the related art, since the tray is not made to stop by making it strike a stopper member, the load acting on the tray is small, the durability of the tray is improved, and there is less trouble. Further, since it is possible to make the tray horizontal carrier stop at the accurate position by controlling the amount of movement of the drive wire in the longitudinal direction, there is no need to provide a stopper member, sensor, etc. for every stopping position of the tray, the configuration is simple and there is less trouble in this respect as well.
The first electronic device tray transporting apparatus according to the present invention and the second electronic device tray transporting apparatus according to the present invention are particularly suitable for use in the chamber section of an electronic device testing apparatus. In the chamber section of an electronic device testing apparatus, it is necessary to convey the tray in a vertical direction and necessary to convey it in a horizontal direction and an improvement of the operating speed of the tray carrier, a reduction of the rate of trouble, an improvement of the durability, and accurate control of the stopping position are sought.
To achieve the fourth object of the present invention, according to the present invention, there is provided an in-chamber member movement mechanism comprising a drive wire for driving a movement member arranged movably in a chamber section with an inside set to conditions different from the external environment; a drive source arranged outside the chamber section and linked with the drive wire so as to make the drive wire move along the longitudinal direction; a drive wire introduction member attached to the chamber wall and forming a through hole through which the drive wire may pass between the inside and outside of the chamber section; and a moisture absorbing member attached to the through hole of the drive wire introduction member and sliding over the outer periphery of the drive wire.
At the chamber inner side of the through hole of the drive wire introduction member is preferably provided a blow hole for blowing out dry air.
The moisture absorbing member is constituted by a felt ring and is attached at the chamber outer side of the through hole.
The two ends of the through hole in the axial direction are preferably provided with seal members substantially air-tightly sealing the inside of the through hole.
The movement member preferably is a carrier for conveying a tray holding devices under test inside the chamber section.
With the in-chamber member movement mechanism according to the present invention, since a drive wire is used to make the in-chamber movement member move, it is possible to control the amount of movement of the drive wire in the longitudinal direction to make the in-chamber movement member (for example, tray horizontal carrier) stop at an accurate position. The amount of movement of the drive wire in the longitudinal direction can be relatively easily controlled by using for example a step motor as the drive source. Further, unlike in the related art, since the tray or other movement member is not made to stop by making it strike a stopper member, the load acting on the movement member is small, the durability of the movement member is improved, and there is less trouble. Further, since it is possible to make the tray horizontal carrier or other movement member stop at the accurate position by controlling the amount of movement of the drive wire in the longitudinal direction, there is no need to provide a stopper member, sensor, etc. for every stopping position of the tray, the configuration is simple, and there is less trouble in this respect as well.
In particular, in the present invention, the through hole of the drive wire introduction member attached to the chamber wall has attached to it a felt ring or other moisture absorbing member. This moisture absorbing member slides over the outer periphery of the drive wire, so seals the through hole and prevents the entry of outside air to improve the insulation and wipes off condensation from the drive wire. Further, by providing a blow hole for blowing dry air at the chamber inner side of the through hole, the dry air blown from the blow hole fills the inside of the through hole and therefore effectively prevents the outside air from entering inside the through hole. As a result, the insulation is improved and condensation is controlled. Further, the dry air blown out from the blow hole also functions to dry away the moisture absorbed by the moisture absorbing member.
The electronic device testing apparatus according to the present invention is provided with an electronic device tray having a tray body provided with a holder in which an electronic device under test is held and a shutter which is attached movably with respect to the tray body and opens and closes an opening of the holder; an operating mechanism for making the shutter move with respect to the holder to open or close the opening; a tray movement mechanism for making the electronic device tray move; an electronic device transfer mechanism for taking out and inserting an electronic device held in the holder in a state where the operating mechanism is used to make the shutter move and open the opening; and a chamber section having positioned inside it a measurement unit for testing the electronic device taken out by the electronic device transfer mechanism.
The operating mechanism preferably has a drive mechanism which makes the shutter move with respect to the tray body in the state where the electronic device tray is stationary. As the drive mechanism, for example a fluid pressure cylinder or electric motor or the like may be mentioned. Further, in accordance with need, a link mechanism or other various operation conversion mechanisms may be used as part of the drive mechanism.
Further, the operating mechanism may be a stopper which catches on the engagement portion of the shutter and makes the shutter move relative to the tray body when the electronic device tray is made to move by the tray movement mechanism.
In this case, the shutter may be opened or closed utilizing the movement of the electronic device tray. For example, it is possible to provide an affixed stopper abutting against only the shutter at the tester side when the electronic device tray is conveyed to the reloading position of the electronic device under test and using the relative movement of the tray body and stopper to open or close the shutter.
The electronic device testing apparatus according to a further aspect of the present invention is provided with a chamber section in which a measurement unit for testing an electronic device is positioned; a tray carrier arranged movably in the chamber section; a drive wire for driving the tray carrier; an electronic device tray arranged detachably with respect to the tray carrier; and an electronic device transfer mechanism for picking and placing an electronic device in the electronic device tray.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.